The article presents the results of the theoretical and practical research on the investments and sources of their financing within the enterprise.The sources of funding, their types and their classification are described in detail and analyzed.The advantages and disadvantages of these external and internal sources of funding are also outlined. From the researches we made, we noticed the methods of financing and we determined that in Moldova the most used model is the financing through the lending mechanism followed by the self-financing. As a result of the investigations we have concluded that we have sources of internal and external financing and their role in the development of enterprises is quite important, because with them an entity can function normally